Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis
The development and implementation of technology that can capture and transform carbon dioxide (CO<sub>2</sub>) is of ongoing interest. To that end, the integration of molecular electrocatalysts into devices is appealing because of the desirable features of molecules, such as the ability...
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MDPI AG
2023-01-01
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| Series: | Inorganics |
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| Online Access: | https://www.mdpi.com/2304-6740/11/1/43 |
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| author | Elahe Tajbakhsh Declan McKearney Daniel B. Leznoff Jeffrey J. Warren |
| author_facet | Elahe Tajbakhsh Declan McKearney Daniel B. Leznoff Jeffrey J. Warren |
| author_sort | Elahe Tajbakhsh |
| collection | DOAJ |
| description | The development and implementation of technology that can capture and transform carbon dioxide (CO<sub>2</sub>) is of ongoing interest. To that end, the integration of molecular electrocatalysts into devices is appealing because of the desirable features of molecules, such as the ability to modify active sites. Here, we explore how the identity of the aliphatic group in 1,4,8,11,15,18,22,25-octaalkoxyphthalocyanine cobalt(II) affects the catalytic behavior for heterogeneous CO<sub>2</sub> reduction electrocatalysis. The alkyl R-groups correspond to <i>n</i>-butoxy, <i>sec</i>-butoxy, and 2-ethylhexoxy. All of the catalysts are soluble in organic solvents and are readily solution-processed. However, the larger 2-ethylhexoxy group showed solution aggregation behavior at concentrations ≥1 mM, and it was, in general, an inferior catalyst. The other two catalysts show comparable maximum currents, but the octa <i>sec</i>-butoxy-bearing catalyst showed larger CO<sub>2</sub> reduction rate constants based on foot-of-the-wave analyses. This behavior is hypothesized to be due to the ability of the sec-butoxy groups to eliminate the ability of the alkoxy oxygen to block Co Sites via ligation. CO<sub>2</sub> reduction activity is rationalized based on solid-state structures. Cobalt(II) phthalocyanine and its derivatives are known to be good CO<sub>2</sub> reduction catalysts, but the results from this work suggest that straightforward incorporation of bulky groups can improve the processability and per site activity by discouraging aggregation. |
| first_indexed | 2024-03-09T12:15:13Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2304-6740 |
| language | English |
| last_indexed | 2024-03-09T12:15:13Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Inorganics |
| spelling | doaj.art-c4efc6d223ae446a8050f634bbeb532d2023-11-30T22:47:30ZengMDPI AGInorganics2304-67402023-01-011114310.3390/inorganics11010043Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction ElectrocatalysisElahe Tajbakhsh0Declan McKearney1Daniel B. Leznoff2Jeffrey J. Warren3Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, CanadaDepartment of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, CanadaDepartment of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, CanadaDepartment of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, CanadaThe development and implementation of technology that can capture and transform carbon dioxide (CO<sub>2</sub>) is of ongoing interest. To that end, the integration of molecular electrocatalysts into devices is appealing because of the desirable features of molecules, such as the ability to modify active sites. Here, we explore how the identity of the aliphatic group in 1,4,8,11,15,18,22,25-octaalkoxyphthalocyanine cobalt(II) affects the catalytic behavior for heterogeneous CO<sub>2</sub> reduction electrocatalysis. The alkyl R-groups correspond to <i>n</i>-butoxy, <i>sec</i>-butoxy, and 2-ethylhexoxy. All of the catalysts are soluble in organic solvents and are readily solution-processed. However, the larger 2-ethylhexoxy group showed solution aggregation behavior at concentrations ≥1 mM, and it was, in general, an inferior catalyst. The other two catalysts show comparable maximum currents, but the octa <i>sec</i>-butoxy-bearing catalyst showed larger CO<sub>2</sub> reduction rate constants based on foot-of-the-wave analyses. This behavior is hypothesized to be due to the ability of the sec-butoxy groups to eliminate the ability of the alkoxy oxygen to block Co Sites via ligation. CO<sub>2</sub> reduction activity is rationalized based on solid-state structures. Cobalt(II) phthalocyanine and its derivatives are known to be good CO<sub>2</sub> reduction catalysts, but the results from this work suggest that straightforward incorporation of bulky groups can improve the processability and per site activity by discouraging aggregation.https://www.mdpi.com/2304-6740/11/1/43carbon dioxide reductioncobaltphthalocyaninesheterogeneous electrocatalysiscatalyst design |
| spellingShingle | Elahe Tajbakhsh Declan McKearney Daniel B. Leznoff Jeffrey J. Warren Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis Inorganics carbon dioxide reduction cobalt phthalocyanines heterogeneous electrocatalysis catalyst design |
| title | Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis |
| title_full | Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis |
| title_fullStr | Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis |
| title_full_unstemmed | Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis |
| title_short | Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis |
| title_sort | heterogenous preparations of solution processable cobalt phthalocyanines for carbon dioxide reduction electrocatalysis |
| topic | carbon dioxide reduction cobalt phthalocyanines heterogeneous electrocatalysis catalyst design |
| url | https://www.mdpi.com/2304-6740/11/1/43 |
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